Refining our understanding of the bioeconomy

Tag Archives: green algae

In this post a first draft is given on a description and the applications of some of the products that can be obtained from brown and green algae. In the case of the polyphenols, I’ve simply introduced an external link due to the incredible amount of information available, that clearly exceeds the scope of this post.

Compound of interest

Compound description / functionality

Applications / market segments (for products)

Brown algae

Alginate with different M/G-ratios and derived products:

Alginic acid (algin, alginate) is a polysaccharide that is abundant in the cell walls of brown algae. (Pheophyceae, mainly laminariales and fucales) and in specific bacteria (acetylated form). Chemically, it is a linear copolymer with homopolymeric blocks of (1-4)-linked β-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks.

Alginates are widely used as waterproofing and fireproofing fabrics, as a gelling agent, for thickening drinks, ice cream and cosmetics, as a detoxifier that can absorb poisonous metals from the blood, as food additives (E number from E400 to E405), healthcare products (rheological properties)… Alginates also show health benefits as dermal fibroblast modulators and antitumoral as well.

Monomer: Mannuronic acid

Difficult to find a not purely chemical description.

No important applications found (yet)

Monomer: Guluronic acid

Difficult to find a not purely chemical description.

No important applications found (yet)

Aldaric acids, obtained by catalytic oxidation of the monomers

Aldaric acids are a group of sugar acids, where the terminal hydroxyl groups of the sugars have been replaced by terminal carboxylic acids, and are characterised by the formula HOOC-(CHOH)n-COOH

As standalone chemical. They can be used as diacid monomers for the preparation of assorted polyamides, labeled polyhydroxypolyamides (PHPAs) or Hydroxylated Nylons.

Laminaran

The molecule laminaran is a storage glucan (a polysaccharide of glucose) found in brown algae.

As a bio-pesticide, it can be used to improve seed germination and protect against foliar fungal infections. Laminaran is claimed to modulate immune responses in mammals. Sulfated laminaran has been shown to have heparin-like properties and to be an elicitor of plant defense reactions against viral infections. Laminaran also has dietary fiber properties.

Mannitol

Mannitol (also referred to as mannite or manna sugar) is a white, crystalline solid that looks and tastes sweet like sucrose.

The pleasant taste and mouthfeel of mannitol also makes it a popular excipient for chewable tablets. Mannitol increases blood glucose to a lesser extent than sucrose (thus having a relatively low glycemic index[14]) and is therefore used as a sweetener for people with diabetes, and in chewing gums. Also, it has a very low hygroscopicity- it does not pick up water from the air until the humidity level is 98%. This makes mannitol very useful as a coating for hard candies, dried fruits, and chewing gums.

Fucoidan

Fucoidan is a sulfated polysaccharide (MW: average 20,000) found mainly in various species of brown algae and brown seaweed.

Fucoidan is used as an ingredient in some dietary supplement products, where it is claimed to be beneficial for cancer prevention, for the prevention of blood clots and for the treatment of gastric ulcers.

Protein

Algae is really the premiere sustainable source of raw materials for food and feed.

For food and feed: Algae can be cultivated in human-made ponds on otherwise unusable desert land, requiring only sunlight and seawater to grow. It’s about 30 times more productive than soy (and 50 times more productive than corn), but requires only 1 percent as much fresh water. It also has a much higher protein content — up to 70 percent, compared with about 10 percent in corn and 40 percent in soy.

Fucoxanthin

It is found as an accessory pigment in the chloroplasts of brown algae and most other heterokonts, giving them a brown or olive-green color.

Some metabolic and nutritional studies carried out on rats and mice at Hokkaido University indicate that fucoxanthin promotes fat burning within fat cells in white adipose tissue by increasing the expression of thermogenin. Fucoxanthin is being looked into for its anti-inflammatory, antinociceptive, and anti-cancer effects. A study has shown that fucoxanthin has strong effects on oxidative stress, oxidative stress-related diseases, and cancers. Fucoxanthin is isolated from a brown algae which has been reported to be a popular health food.

Taurine

A conditionally indispensable organic acid, required for protein digestion. Also, 2-aminoethanesulfonic acid, is an organic acid widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine, and accounts for up to 0.1% of total human body weight.[1] Taurine has many fundamental biological roles, such as conjugation of bile acids, antioxidation, osmoregulation, membrane stabilization, and modulation of calcium signaling. It is essential for cardiovascular function, and development and function of skeletal muscle, the retina, and the central nervous system. Taurine is unusual among biological molecules in being a sulfonic acid, while the vast majority of biologically occurring acids contain the more weakly acidic carboxyl group. While taurine is sometimes called an amino acid, and indeed is an acid containing an amino group, it is not an amino acid in the usual biochemical meaning of the term, which refers to compounds containing both an amino and a carboxyl group.

Taurine is essential for cardiovascular function, and development and function of skeletal muscle, the retina, and the central nervous system. It also acts as an antioxidant and protects against toxicity of various substances (such as lead and cadmium). Additionally, supplementation with taurine has been shown to prevent oxidative stress induced by exercise. taurine supplementation is possibly beneficial for the prevention of atherosclerosis and coronary heart disease. Dietary taurine has a blood cholesterol-lowering effect in young overweight adults. Furthermore, body weight also decreased significantly with taurine supplementation. Taurine has also been shown to help people with congestive heart failure by increasing the force and effectiveness of heart-muscle contractions. Taurine levels were found to be significantly lower in vegans. In cells, taurine keeps potassium and magnesium inside the cell, while keeping excessive sodium out. In this sense, it works like a diuretic. Because it aids the movement of potassium, sodium, and calcium in and out of the cell, taurine has been used as a dietary supplement for epileptics, as well as for people who have uncontrollable facial twitches. Taurine produces an anxiolytic effect and may act as a modulator or antianxiety agent in the central nervous system by activating the glycine receptor. Taurine is necessary for normal skeletal muscle functioning.

Phlorotannins are a type of tannins found in brown algae such as kelps and rockweeds[1] or sargassacean species,[2] and in a lower amount also in some red algae.[3] Contrary to hydrolysable or condensed tannins, these compounds are oligomers of phloroglucinol[4] (polyphloroglucinols).[5] As they are called tannins, they have the ability to precipitate proteins.

It has demonstrated that phlorotannins can have anti-diabetic, anti-cancer, anti-oxidation, antibacterial, radioprotective and anti-HIV properties. However, in vivo studies on the effects of these compounds are lacking, most of the research having so far been done in vitro.

Phloroglucinols

Phloroglucinol is an organic compound that is used in the synthesis of pharmaceuticals and explosives. It is a phenol derivative with antispasmodic properties that is used primarily as a laboratory reagent.

It is also used as a treatment for gallstones, spasmodic pain and other related gastrointestinal disorders. It has a non-specific spasmolytic action on the vessels, bronchi, intestine, ureters and gall bladder, and is used for treating disorders of these organs. It is the main ingredient of the drug Spasfon, commercialized in France, where it is one of the most sold drugs. Phloroglucinol is mainly used as a coupling agent in printing. It links diazo dyes to give a fast black. It is useful for the industrial synthesis of pharmaceuticals (Flopropione) and explosives (TATB, trinitrophloroglucinol, 1,3,5-trinitrobenzene). Phloroglucinolysis is an analytical technique to study condensed tannins by means of depolymerisation. Phloroglucinol is a reagent of the Tollens’ test for pentoses. A solution of hydrochloric acid and phloroglucinol is also used for the detection of lignin (Wiesner test). It is also part of Gunzburg reagent, an alcoholic solution of phloroglucinol and vanillin, for the qualitative detection of free hydrochloric acid in gastric juice.

Rhamnose is an unusual sugar that is found primarily in plants and some bacteria. Unlike most natural sugars, it is found in an L configuration instead of the usual D configuration. It forms a major structural component of plant cell walls and is also bound to other compounds, such as phenolics.

Combined with lipids (produced by a bacteria), a natural surfactant is obtained. There are myriad other uses for this sugar. For instance, there is an overexpression system in which the production of the desired gene is triggered by adding sterilized rhamnose to the genetically engineered bacteria. A rhamnose test is available for intestinal permeability in humans. Many prescription drugs, such as non-steriodal anti-inflammatory drugs (NSAIDs), can cause intestinal damage that manifests as leakage through the intestines. Having patients drink a solution of lactulose and L-rhamnose is one way of testing for this condition.

Monomers: iduronic acid

Difficult to find a not purely chemical description.

No important applications found (yet)

Most information has been obtained from common sources, such as Wikipedia.